Heart disease has long been linked to high cholesterol, blood pressure, and poor diet—but what if your gut bacteria also played a role? Recent research is uncovering a surprising connection between the microbes in your intestines and your risk of developing cardiovascular disease. In particular, certain bacteria appear to produce compounds that may increase inflammation, damage blood vessels, and promote plaque buildup.

Let’s break down what scientists have discovered about how gut bacteria influence heart health.

The Culprit: TMAO and Its Microbial Origins

One of the most studied gut-derived compounds linked to heart disease is TMAO (trimethylamine-N-oxide) (1). This substance is produced when certain gut bacteria break down nutrients like choline, lecithin, and carnitine, which are commonly found in red meat, eggs, and dairy (2).

Here’s how it works:

  1. You eat a meal containing choline or carnitine.
  2. Specific gut bacteria convert these compounds into trimethylamine (TMA).
  3. Your liver converts TMA into TMAO.
  4. TMAO enters your bloodstream and, according to studies, may contribute to arterial plaque buildup, inflammation, and impaired cholesterol metabolism (2).

Higher blood levels of TMAO have been consistently associated with increased risk of heart attack and stroke (3).

This doesn’t mean that choline and carnitine are inherently bad for you. Instead, this research seems to imply that the problem is an inappropriate level of conversion of them into TMA by gut bacteria.

Which Bacteria Are Involved?

Not all bacteria produce TMA. Research shows that certain strains in the Firmicutes and Proteobacteria phyla are more likely to convert choline and carnitine into TMA (4).

At the same time, other gut microbes may actually help reduce TMAO levels by:

  • Competing with TMA-producing strains for resources
  • Promoting anti-inflammatory activity
  • Enhancing gut barrier integrity, which helps prevent systemic inflammation

What You Can Do to Protect Your Gut and Your Heart

If you’re concerned about cardiovascular health, consider taking steps that support both your heart and your microbiome:

1. Eat More Prebiotic Fiber

Foods like oats, garlic, onions, leeks, and asparagus nourish beneficial bacteria that may help reduce TMAO-producing populations (5).

2. Limit Red Meat and Processed Foods

Reducing intake of carnitine-rich foods may directly lower TMAO production.

3. Increase Fermented Foods

Kimchi, sauerkraut, kefir, and yogurt introduce beneficial microbes that help diversify the microbiome.

4. Try Targeted Supplements

Emerging supplements like IgY-based products may help reduce populations of inflammatory or harmful bacteria while supporting microbial balance.

5. Prioritize Gut Diversity

The more diverse your gut microbiome, the more resilient and protective it becomes.

Final Thoughts

Your gut bacteria may be doing more than just digesting your food. It could also be influencing your long-term cardiovascular health. By understanding the role of gut-derived compounds like TMAO and the microbes that produce them, you can make smarter dietary and lifestyle choices that protect both your heart and your microbiome.

Explore gut-targeted strategies to support whole-body wellness at igynutrition.com.

References

  1. https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2023.1085041/full
  2. https://www.nature.com/articles/nature09922
  3. https://pubmed.ncbi.nlm.nih.gov/31918665/
  4. https://pubmed.ncbi.nlm.nih.gov/25784704/
  5. https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-025-06806-7